• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.33-45
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• 1978

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1975 following after the selection of 1974, twenty trees from each of three natural populations of the species were selected and their open-pollinated seeds were collected, and the locations and conditions of the populations ate presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our second report of this series, in which Myong-Ju and Ul-Jin populations were regarded to be superior phenotypically to suweon population. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period (1931~1960) measured from the nearest meteorological stations to each population are shown in fig.2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Suweon area, population 6, were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index, i.e., length to diameter ratio are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be highly significant in population differences and family differences within population. 3. The morphological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed-wing length, seed-wing index, seed weight, seed-length and seed index but not among the populations in the other observed traits. The values of correlation coefficient between the characters of cone and seed are given in table 10 and the positive significant correlations can be observed in the most parts of the compared traits. 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 and 1-1 seedling height of these progenies. But the differences in root collar diameter are shown only among families within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. The number of stomata row on both sides of needle and the serration density were measured in the seedlings from each of the families of the three populations. As shown in table 15, statistical differences are considered to be significant among the populations and among the families within population in serration density but not among the populations in stomata row on both sides of the needle. The results differ from those of the third report of this series. Even if one of the reason seems to be the diversity of selected populations, it could not be confirmed definitely. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.6
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• pp.790-797
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• 2015

This study tried to evaluate the safety and economical benefit of Nitrox-diving by comparing with Air diving. We used actual diving data which was recorded in construction site of the Busan-Geoje fixed link immersed tunnel in 2010. The study method was to assort and analyze the diving data by divers, depth, breathing air, and diving table. Furthermore, the study examined the possibility of outbreak decompression sickness by comparing Nitrox diving and Air diving in no-decompression limit time, decompression time, working time. As a result, this study confirms that if certain diver breathe Nitrox for diving and oxygen for decompression, not only the risk of decompression sickness could be minimized, but also duration of decompression could be shortened. Moreover, it was estimated that a remarkable difference(more than 3 times) between actual duration of underwater construction period and virtual construction period by using air. As a result, the study confirmed that Nitrox diving is more efficient and economical than Air diving in physically limited and hazardous diving environment.

• Progress in Medical Physics
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• v.24 no.4
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• pp.237-242
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• 2013

In the intracranial regions, an accurate delineation of the target volume has been difficult with only the CT data due to poor soft tissue contrast of CT images. Therefore, the magnetic resonance images (MRI) for the delineation of the target volumes were widely used. To calculate dose distributions with MRI-based RTP, the electron density (ED) mapping concept from the diagnostic CT images and the pseudo CT concept from the MRI were introduced. In this study, the look up table (LUT) from the fifteen patients' diagnostic brain MRI images was created to verify the feasibility of MRI-based RTP. The dose distributions from the MRI-based calculations were compared to the original CT-based calculation. One MRI set has ED information from LUT (lMRI). Another set was generated with voxel values assigned with a homogeneous density of water (wMRI). A simple plan with a single anterior 6MV one portal was applied to the CT, lMRI, and wMRI. Depending on the patient's target geometry for the 3D conformal plan, 6MV photon beams and from two to five gantry portals were used. The differences of the dose distribution and DVH between the lMRI based and CT-based plan were smaller than the wMRI-based plan. The dose difference of wMRI vs. lMRI was measured as 91 cGy vs. 57 cGy at maximum dose, 74 cGt vs. 42 cGy at mean dose, and 94 cGy vs. 53 at minimum dose. The differences of maximum dose, minimum dose, and mean dose of the wMRI-based plan were lower than the lMRI-based plan, because the air cavity was not calculated in the wMRI-based plan. These results prove the feasibility of the lMRI-based planning for brain tumor radiation therapy.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.351-352
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• 2012

UV LED에서 p-GaN층의 높은 일함수와 자체 면저항이 크기 때문에 current spreading layer인 ITO (indium tin oxide) 투명전극이 사용되고 있다. 따라서 높은 UV 파장대 투과율과 낮은 면 저항이 매우 중요하다. 본 연구에서, RF magnetron sputter를 사용하여 ITO 투명전극을 glass(boro33)에 120 nm 두께로 증착하였다. 그 후 RTA (rapid thermal annealing)을 이용해 120초 동안 $600^{\circ}C$에서 Air, $N_2$ (15 sccm), vacuum 환경에서 열처리를 하여 UV-Vis-NIR spectrophotometer를 사용해 ITO 박막의 투과율을 측정하고, Hall measurement system을 이용하여 전기적 특성을 측정하였다. Fig. 1과 같이 열처리 환경에 따라 ITO 박막의 투과율이 변하고 또한 Table 1과 같이 전기적 특성도 변함을 알 수 있었다. Air 환경에서의 열처리는 reference 샘플과 비교 했을 때 400 nm 이하의 파장에서 투과율이 증가하였지만 400 nm 이상의 파장에서는 투과율이 낮아짐을 볼 수 있고, 면 저항 (Ohm/sq)은 오히려 reference (as deposited) 샘플과 비교하여 24 Ohm/sq 증가하는 것을 알 수 있었다. 반면에 $N_2$, vacuum 환경에서 열처리는 reference (as deposited) 샘플 보다 380 nm 파장대에서 16% 정도 높은 투과율을 보였고, 면저항 역시 2배 이상 낮아졌다. 둘 다 비슷한 투과율과 면저항을 나타내었지만 vacuum 환경이 좀 더 우수한 광학적 특성을 나타내었고 반면에 $N_2$ 환경은 좀 더 낮은 면저항을 나타내었다. ITO 박막을 증착한 후 vacuum 환경에서 열처리를 통하여 제작된 UV-LED (중심 파장 380 nm)가 Fig. 2와 같이 입력 전류 450 mA에서 광출력이 46% 정도 향상 되었고 안정된 I-V 특성 보였다.

• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.85-96
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• 2008

An authentication procedure on wired and wireless network will be done based on the registration and management process storing both the user's IP address and client device's MAC address information. However, existent MAC address registration/administration mechanisms were weak in MAC Spoofing attack as the attacker can change his/her own MAC address to client's MAC address. Therefore, an advanced mechanism should be proposed to protect the MAC address spoofing attack. But, existing techniques sequentially compare a sequence number on packet with previous one to distinguish the alteration and modification of MAC address. However, they are not sufficient to actively detect and protect the wireless MAC spoofing attack. In this paper, both AirSensor and AP are used in wireless network for collecting the MAC address on wireless packets. And then proposed module is used for detecting and protecting MAC spoofing attack in real time based on MAC Address Lookup table. The proposed mechanism provides enhanced detection/protection performance and it also provides a real time correspondence mechanism on wireless MAC spoofing attack with minimum delay.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.369-372
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• 2008

This study analysis fundamental properties of high-strength concrete corresponding to W/B ratio for suggested table of high strength concrete, mixed with premixed cement. As a result of this study, the amount of using air entraining and high-range water reducing agent for intended slump flow and air content decreased as W/B increased, and the setting time corresponding to the W/B ratio delayed as W/B ratio increased except 20% W/B ratio. The compressive strength according to W/B ratio decreased as W/B ratio increased, and there was no great deferent as the intended slump flow. Also it could possible to use this study at work as the correlation coefficient is high enough as 0.9646 substituting B/W and compressive strength for the regression formula.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.395-400
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• 2017

The paper discussed the air-to-fuel ratio control of automotive fuel-injection systems using the cerebellar model articulation controller(CMAC) neural network. Because of the internal combustion engines and fuel-injection's dynamics is extremely nonlinear, it leads to the discontinuous of the fuel-injection and the traditional method of control based on table look up has the question of control accuracy low. The advantages about CMAC neural network are distributed storage information, parallel processing information, self-organizing and self-educated function. The unique structure of CMAC neural network and the processing method lets it have extensive application. In addition, by analyzing the output characteristics of oxygen sensor, calculating the rate of fuel-injection to maintain the air-to-fuel ratio. The CMAC may easily compensate for time delay. Experimental results proved that the way is more good than traditional for petrol control and the CMAC fuel-injection controller can keep ideal mixing ratio (A/F) for engine at any working conditions. The performance of power and economy is evidently improved.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.208-216
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• 2019

Objective: The aim of this study is to control residual chemicals or by-products generated in chambers during preventive maintenance (PM) in the semiconductor manufacturing industry. We designed local exhaust ventilation using computational fluid dynamics (CFD). Methods: The air flow characteristics and capture efficiency between rectangular and slot hoods were compared numerically. The software Fluent 18.1 was used to estimate uniform velocity distribution and capture efficiency for contaminants. A metal from group 15 in the periodic table was released at the bottom of the chamber to simulate emissions. Results: The slot hood had a higher capture efficiency than a rectangular hood under the same conditions because the slot hood provided uniform air flow and higher face velocity. Also, there was no rotating swirl in the plenum for slot, that is why slot had better efficiency than rectangular even though they had similar face velocity. With less than 10 slots, the capture efficiencies for contaminants were nearly 95%. The optimum conditions for a hood to achieve high efficiency was 8 to 10 slots and a face velocity over 1 m/s. Conclusions: Well-designed ventilation systems must consider both efficiency and convenience. For this study, a slot hood that had high capture efficiency and no work disturbance was designed. This will contribute to protection of the worker's health in a PM area and other areas as well. Also, this study confirms the possibility of the application CFD in the semiconductor fabrication industry.

• Magazine of the Korean Society of Agricultural Engineers
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• v.19 no.1
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• pp.4323-4337
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• 1977

The study was to estimate the effect of the rise of water temperature in the warm water pool and to make contribution to the establishment of reducing to a damage of cool water as well as to the planning for warm water pool. This observation was performed in Wudu warm water pool located at Wudu-Dong of Chuncheon for two years from 1975 to 1976. The results were showed as follows; 1. The daily variation of water temperature was the least for inset (No.1; 0.6$^{\circ}C$) the second for middle overflow (No2: 3$^{\circ}C$, No.3; 2.3$^{\circ}C$) and another for outflet (No.4; 3.6$^{\circ}C$, No.5; 3.8$^{\circ}C$) And the highest reaching time of water temperature in each block was later about 1 hour than the time at which air temperature happend in the daytime. So, the variation of water temperature was sensitive to the variation of air temperature 2. The monthly variation of water temperature at each measuring point was plotted to be increased with increase in air temperature till August (Mean monthly rising degree; No.1; 1.15$^{\circ}C$, No.2; 1.7$^{\circ}C$, No.3; 1.73$^{\circ}C$, No.4; 2.08$^{\circ}C$, No.5; 2.0$^{\circ}C$), and expressed gradually descended influence upon water temperature after August. 3. The mean temperature of inflow folwed in warm Water pool was 7.5∼12.5$^{\circ}C$, and outflow temperature was described as 13.4∼22.5$^{\circ}C$ to be climbed. And So, the rising interval of water temperature was shown as 6.7∼10.4$^{\circ}C$. 4. The correlation between the rising of water temperature and the weather condition was found out highly significant. As the result, their correlation coefficents of water temperature depending on mean air temperature, ground temperature, wind velocity and relative humidity were to be 0.93, 0.90, - 0.83 and 0.71 respectively. But there was no confrimation of the correlation on the clouds, sunlight time, volume of evaporation, and heat capacity of horizontal place. 5. The water temperature of balance during the period of rice growing in Chuncheon district was shown as table 10, and the mean of whole period was calculated as about 23.7$^{\circ}C$. 6. The observed value of the outflow temperature passed through the warm water pool was higher than that of computed, the mean difference between two value was marked as 1.15$^{\circ}C$ for blockl, 1.18$^{\circ}C$ for block2, and 0.47$^{\circ}C$ for block3, respectivly. Therefore, the ratio on the rising degree between the observed and computed were shown as 53%, 44%, and 18%, mean 38% through each block warm water pool (referring item $\circled9$ of table 11,12, and 13). Accordingly, formula (4) in order to fit for each block warm water pool was transfromed as follow; {{{{ { theta }_{w } - { theta }_{ 0} =[1-exp LEFT { { 1-(1+2 varphi )} over {cp } CDOT { A} over { q} RIGHT } ] TIMES ( { theta }_{w } - { theta }_{ 0}) TIMES C }}}} Here, correction coefficinent was computed 1.38, and being substituted 1.38 for C in preceding formula, the expected water temperature will be calculated to be able to irrigate the rice paddy. As the result, we can apply the coefficient in order to plan and to construct a new warm water pool.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.327-353
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• 2017

The issue submitted to the Court of Justice on the merits of case C---573/13 originated from a claim brought in the context of a dispute between Air Berlin and the German Federal Union of Consumer Organisations and Associations. The challenge concerned the way in which air fares were displayed in Air Berlin's computerised booking system. The system was organised in such a way that, after selecting a date and a departure airport, one would find all possible flight connections in a summary table. However, the final price of the ticket was displayed only for the clicked connection, and not for all connections, thus preventing customers from being able to compare such price with the prices of other connections. The German Federal Union took the view that this practice did not meet the requirements laid down by Article 23 of Regulation (EC) No. 1008/2008, which requires transparency in the prices set for air services. This led the German State to bring an injunctive action to cause Air Berlin to discontinue said practice. The claim was upheld at both the application and appeal stage of the relevant proceedings. Subsequently, Air Berlin submitted the matter to the German Federal High Court, which decided to stay the proceedings and ask for a preliminary ruling from the Court of Justice as to 1. whether Article 23 of Regulation (EC) No. 1008/2008 must be interpreted as meaning that, during the computerised booking process, the final price to be paid must be indicated at all times when prices of air services are shown, including when they are shown for the first time; and 2. whether, during the computerised booking process, the final price must be indicated only for the air service specifically selected by the customer or for each air service shown. In a nutshell, the Court, by the here---discussed judgment determined that Article 23 of Regulation (EC) No. 1008/2008 must be interpreted as meaning that, in the context of a computerised air ticket booking system, the final price to be paid must be indicated not only for the air service specifically selected by the customer, but also for each air service in respect of which the fare is shown. Clearly the above judgment will place air companies under an obligation to update and adjust (when needed) their computerised ticket booking and payment systems, in consideration of the primary need for consumers to be aware at all times of the actual price payable for a ticket and be able to compare the price of the service selected with the prices for other air services in respect of which the fare is shown.